Longevity and Endurance – Smirk better than Smile

What can happen over 10 years? 100 years?
What can happen over 10 years? 100 years?

What can simple long-term data from thousands of recreational marathoners tell us about living a better life? Whether it be for your work, your hobbies, your health or even, specifically, your marathoning, these insights will empower you to create a better future for yourself.

You will have realized by now that life is a marathon, not a sprint. Though it may not seem so, today’s conversation is really, in essence, nothing to do with running. It is about some lessons that you and I can learn from observing the actions of thousands of others.


Key Lessons to Take Away
Guidance for Life – Lifestyle Guidance
*  * don’t stop
*  * consistency
*  * never too late


Key Lessons to Take Away [top]

To tell you where we are going today before we set off, here are the 3 key takeaways:

  • Once you start, don’t stop – a smirk is great, but even a smile is better than nothing at all [jump]
  • Consistency matters – you do not have to be better than others [jump]
  • It is never too late to start – but don’t leave it until too late [jump]


Background [top]

If there is anything some scientists know and most doctors often enjoy being wilfully blind to it is that sensible lifestyle protocols are what will extend your Healthspan for you, not prescription or OTC drugs.

Although it is still an extremely tiny percentage of the population that is enlightened, and, perhaps, you are in that sliver, we only need a critical mass of early adopters to make a sea change in the nation’s health. A question still remains, how do you keep yourself on track for the long run? [Dying by 80, Living to 110]

Of the things we do physically that are good for our health, sleep and food are typically always pleasurable. Assuming you enjoy eating Healthspan extending foods like I do, and get at least as good sleep as I do, you’re already onto a good thing. Keeping them on track, decade after decade is extremely easy. But what about exercise?

It is true that we feel happy when we are in a state of flow during exercise and that physical exercise is literally a wonder drug (that, fortunately, cannot be patented). But, how do you stay committed to it, year after year, decade after decade? A good starting point is to have the right expectations.

I have explained earlier, why you need not run. I have also explained the wisdom behind why I don’t care about your ultra. But what can we learn from the large number of runners who pound the streets throughout the year and do it for many years? What are the lessons for the non-runners among us?

Adults are constantly aging. We can do things to reverse our biological age, and there is a genetic upper limit to how much can be reversed. [Aging and Time Travel]

In order to examine how large numbers of people stay committed to a physical activity we look at those who ran a distance running race event for many years in a row. Any podgy papa or massive mama can run in a “parent’s sprint race” at the school’s sports day with no exercise all year round. But those who present themselves at a 42km, 21km or even 5km race routinely exhibit compliance with their belief that consistent physical activity, in the long run, is both a driver and a marker of better health.


Data [top]

Race data from 2010 to 2019 for 10 years of the Mumbai Marathon is the primary dataset. A parallel “control” dataset of 10 years of the Airtel Delhi Half Marathon is used to confirm that the effects that we see are not race-specific but tell a story about the human population rather than a specific race event.

Quick Note on Popular Names: There are many popular combinations of name-surname that are more popular than others. I call these “Popular Names”. I can bet that you will never find two runners with the name ‘Sukhpreet Patel’ in a race (a Sukhpreet is typically never Patel from birth, and a Patel will never name their child Sukhpreet). On the other hand, good luck trying to figure out which Rajesh Shah out of the 14 in a race, is your friend. In our data, out of 66,391 names, there were 2,249 names that appeared at least twice in a single race. To reduce the likelihood of errors, we remove these names from the dataset knowing that this will not introduce any bias in our results.


Methodology [top]

The focus is on participants who ran the same race many years in a row. With 10 years of race history, we focus on ‘many’ being ‘more than 5’ i.e. 6, 7, 8, 9 or 10 years in a row. For example, this could be someone who ran the half-marathon 6-years in a row from, say, 2010 to 2015. Or, for example, someone who ran the full-marathon 8 years in a row, from, say 2012 to 2019. There were 943 such runners whose race numbers provide us guidance.

The race net-finish-times are standardized for each person so that they are comparable, both across runners and over the years for a given runner. This standardization for any given runner’s race time in a specific race event is done using the simple transformation:

% difference in net-finish-time of this runner for this year relative to the fastest net-finish-time of this runner over all the years raced

This could be loosely interpreted as “how did a runner perform each year relative to his potential?” We never really see true genetic potential (see Genetic Potential Fitness) but to guide our lessons to take away from this exercise, this is a useful interpretation.


Guidance for Life – Lifestyle Guidance [top]

It is extremely important to note that although we have used running as a backdrop (because we have data for it!) the lessons from it apply to anything that you do that is good for you. If you are not into running, but into improving your intake of fruits, or spending more time learning the piano, go ahead and switch ‘run’ for ‘eat fruit’ or ‘play piano’.

Once you start, don’t stop – a smirk is great, but even a smile is better than nothing at all [top]

I had already told you, 3 years ago, that you might run slower sooner than you think. The most valuable observation that we can make from the additional data since then is that this slowing down continues to be true. Moving from 7 years to 10 years of running history, the phenomenon is clear.

The Smile is Consistent
The Smile is Consistent

The Smile

We see a ‘smile’ i.e. on average, runners getting faster in the initial years and then slowing down. This smile effect is easy to explain. The typical urban recreational runner takes up running following years of being sedentary. Like you, they also have constraints such as family or business responsibilities. With that in mind, they reach something close to their athletic potential for their age and genes. They then transition to going easier on the training load with the goal of “maintaining” an active lifestyle. This requires year-long consistency without pushing the limits endlessly, and, as is natural, the race times get slower.

[For the geeky amongst you, I shall add that taken in a piecewise fashion, each of the points plotted is statistically significantly different from the immediately adjacent ones. So, what you see visually is also statistically true. The smile is not just visual, it is statistically true!]

The Smirk

Smirk > Smile > Sedentary
Smirk > Smile > Sedentary

Hidden in the population that produced that smile are those who actually have a smirk. They are the ones whose performance stayed close to their 10-year-personal-best even after 10 years. They, perhaps, have fewer binding constraints, or did not improve faster in the early years, and so can continue to improve. Or, even more laudable, they are the ones who manage to stay closer to their personal best times year-after-year.


Consistency matters – you do not have to be better than others [top]

Someone who runs even a 5km race once a year, and trains through the year for it, is demonstrating a lifestyle marker for good health. It is lovely to see from the data that those who ran the half-marathon for 10 years in a row, or the full-marathon for 10 years in a row were not typically fast runners. For instance, the red vertical lines in this graph highlight the race times of those who ran the Full Marathon in Mumbai for 10 years in a row.

You don't have to be fast to be awesome
You don’t have to be fast to be awesome

I was excited to spot that my regular Sunday running buddy is the fastest among those who ran the Half Marathon 10 years in a row. For those of you who complain about age or work pressures, he’s happy for me to tell you that he’s well over 50 and has been CEOs of large institutions for many years. You have heard me speak about why I don’t care about your podium finish (or mine). I’m happy that he is as fast as he is, but what I want us to take away from this information is that he performs well professionally because of his focus on exercise, not despite him having to make time to run.

Better to live longer than run fast
Better to live longer than run fast


It is never too late to start – but don’t leave it until too late [top]

Recreational endurance runners, especially in India, are typically approaching middle-age or going through it. Those who are aware of the smile effect will accept it as part of the journey and keep their attention on maintaining good physical health. Being aware of what is possible is important when attempting anything. If you do it well, you might even manage a smirk rather than a smile.

Definitely smile when you run! Definitely smile when you eat your greens! Definitely smile when you play the piano.



Dr Purnendu Nath spends his waking hours focusing on helping individuals and organizations reach their goals, to make the world a better place. He speaks, writes and advises on topics such as finance, investment management, discipline, education, self-improvement, exercise, nutrition, health and fitness, leadership and parenting.


  1. Txs Puru Sir for sharing your thoughts on Longevity and Endurance. Really appreciate your time and effort. Jai hind Colonel Dr Suhag


  2. Hi Puru

    I have been following you since 2016. And I need some help. I am looking to improve my overall life and seek help.

    Are you taking life coaching now ? If so, what are the charges like ?

    Look forward to hear from you.

    Regards Bharat


    • Thanks for your comment. Although it appears like running a marathon is super tough… actually, it’s not. Just give yourself 6 months to build up gradually, safely… and you will wonder why you thought it was a super challenging goal. The trick is to get started and take one safe and sure step at a time… Good luck!


  3. As always another great post backed with a lot of data. The same premise can also be said of businesses, there are those that sprint out of the gate and then quickly slow down. But, there are some that are consistent like the turtle.


    • Thanks for that observation, Manish!
      And one similar problem in the business setting, like in the case of marathoning or piano-playing, is that those who get excited by, and then define themselves as, being sprinters, give up once they can’t maintain the pace (instead of opening their eyes to the better possible outcome from being a turtle)


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